adding users in php with shell_exec() command?

[heyland]

Hey

So i'm working on a small simple servermanagement app in php to manage the ubuntu server.

Someone told me I have to use the shell_exec() command in php to execute the commandlines in ubuntu.

I did a ping test wich works...

 $ping = shell_exec('ping -c 1 -w 1 google.com');
echo "<pre>{$ping}</pre>"; 
  

But now I want to add a user, so from my understanding I could just do this...

 $user = $_POST['user'];
$out = shell_exec('adduser' .$user); 
  

But I can't seem to add any users.
When I list my user using "users" command in ubuntu, I only see my loginname.

How do I add users using php?

[heyland]

Please someone help me out. I need to do a lot of root command through this php application.

I need to know how I can do root commands via php
I know it's shell_exec() but not all the commands work.

Can someone help me out?

[heyland]

do I need to do something on the ubuntu server before I can use this shell_exec() function?

I've tried everything I could find and I'm at the end of my rope here!